Arianka is the Goddess of discipline either militarily or maternal and is thus followed by her legion of fanboys and warriors. This would make her an enemy of Tzeentch and potentially Malal and a potential would-be girlfriend of Khorne, unfortunately for her, Khorne has already chosen Valkia the Bloody as his waifu.

She is also Warhammer's Sleeping Beauty, this lazy bitch has been dozing off ever since Tzeentch found her to be a threat to his grand designs of lulz; he lured her and then trapped her inside of a coffin made of Laihtero, the rarest form of Gromril which resembles a crystal that constantly emits soft light (How the Goddess of Discipline fell for that, we have no fucking clue). Tzeentch then threw away the keys into the mortal planes and is now hidden somewhere like a really dickish game of Where's Waldo. The coffin itself was hidden beneath the Empire city of Praag, capital of Kislev. Her sword Laihtendrung was also made of Laihtero.

Kaleb Daark, Malal's Champion, was tasked with killing her to prove his worth. He was lead to her coffin (which Skaven had previously tried to destroy via flamethrowers) and endeavored to find the keys to kill her although this was chapter three of a four chapter series (the fourth was never released) so he likely didn't succeed. This plot was never brought up again because of legal issues involving Malal although it makes Arianka the last of the Chaos Gods of Law to be mentioned and thus the most canon of the three.

How the End Times might have effected Arianka can only be speculated at. Did she die when the old world got nommed by Chaos? Is her coffin and keys now floating around in space, or have fallen into the nine realms? Who knows, though since there hasn't been so much as a peep out of any of the Gods of Law in Age of Sigmar so far, odds aren't looking good.